This invention relates generally to field emission displays and manufacturing methods, and more particularly to field emission displays having focusing grids.
As is known in the art, field emission displays (FEDS) include an array of field emitting cathodes, a cathodoluminescent anode, and an array of control electrodes. Each one of the control electrodes is associated with a corresponding display pixel and controls the flow of electrons between the cathodes and the corresponding anode pixel. In a monochromatic array, each pixel corresponds to either a so-called "black" or "white" display luminescence; in a color display each pixel corresponds to a luminous blend of a plurality of, typically three colors.
In order to achieve a relatively bright display, (i.e., up to the order of 10,000 foot lamberts) with typical cathodoluminescent efficiencies, a voltage in the order of 10,000 volts is required between the cathode and anode. In order to reduce the effect of electron beam spreading and its concomitant reduction in picture resolution, cathode to anode separations of less than 3-4 millimeters are required. However, in order to prevent arcing between the anode and cathode with 10,000 volts therebetween, an anode to cathode separation in the order of 3-4 millimeters, or greater, is required. Thus, a compromise must be made between resolution and brightness.